function throttle(fn,delay) {
    var t=null,
        begin=new Date().getTime();
    return function(){
        var _self=this,
            args=arguments,
            cur=new Date().getTime();
        clearTimeout(t); 
        if (cur-begin>=delay) {
            fn.apply(_self,args);
            begin=cur;
        } else {
            t=setTimeout(()=>{
            fn.apply(_self,args);
            },delay) 
        }
    }    
}
export {
    throttle
}